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3 years ago

I NEED HELP PLS!!!!

Mathematics

1 answer:

hram777 [196]3 years ago

5 0

Answer:

Step-by-step explanation:

For these kind of problems, its best to use a Venn Diagram.

Lets break down the information:

There are 50 students total.

25 take Math competiton classes.

29 take Geometry

12 take history and no math classes

19 take both math classes

Now, make a Venn Diagram.

[Look at the photo attached. Also, the blank spaces in the Venn Diagram are ones that no student takes.]

The 12 taking history and no math classes and 3 kids not taking any of those classes look like they're the only ones not taking either math class.

12 + 3 = 15.

So the answer is 15.

[I'm not sure if this is correct or if I made a mistake so please let me know! Thank you! I hope this helps!]

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Please could you find the answers to the questions in the attachment.

Fudgin [204]

( $\frac{x1+x2}{2} , \frac{y1+y2}{2}$ )we need 3 equations
1. midpoint equation which is ( $\frac{x1+x2}{2} , \frac{y1+y2}{2}$ ) when you have 2 points

2. distance formula which is D= $\sqrt{(x2-x1)^{2}+(y2-y1)^{2}}$

3. area of trapezoid formula whhic is (b1+b2) times 1/2 times height

so

x is midpoint of B and C
B=11,10
c=19,6
x1=11
y1=10
x2=19
y2=6
midpoint=( $\frac{11+19}{2} , \frac{10+6}{2}$ )
midpoint=( $\frac{30}{2} , \frac{16}{2}$ )
midpoint= (15,8)

point x=(15,8)

y is midpoint of A and D
A=5,8
D=21,0
x1=5
y1=8
x2=21
y2=0
midpoint=( $\frac{5+21}{2} , \frac{8+0}{2}$ )
midpoint=( $\frac{26}{2} , \frac{8}{2}$ )
midpoint=(13,4)

Y=(13,4)

legnths of BC and XY
B=(11,10)
C=(19,6)
x1=11
y1=10
x2=19
y2=6
D= $\sqrt{(19-11)^{2}+(6-10)^{2}}$
D= $\sqrt{(8)^{2}+(-4)^{2}}$
D= $\sqrt{64+16}$
D= $\sqrt{80}$
D= $4 \sqrt{5}$
BC= $4 \sqrt{5}$

X=15,8
Y=(13,4)
x1=15
y1=8
x2=13
y2=4
D= $\sqrt{(13-15)^{2}+(4-8)^{2}}$
D= $\sqrt{(-2)^{2}+(-4)^{2}}$
D= $\sqrt{4+16}$
D= $\sqrt{20}$
D= $2 \sqrt{5}$
XY= $2 \sqrt{5}$

the thingummy is a trapezoid
we need to find AD and BC and XY
we already know that BC= $4 \sqrt{5}$ and XY= $2 \sqrt{5}$

AD distance
A=5,8
D=21,0
x1=5
y1=8
x2=21
y2=0
D= $\sqrt{(21-5)^{2}+(0-8)^{2}}$
D= $\sqrt{(16)^{2}+(-8)^{2}}$
D= $\sqrt{256+64}$
D= $\sqrt{320}$
D= $4 \sqrt{2}$
AD= $4 \sqrt{2}$

so we have
AD= $4 \sqrt{2}$
BC= $4 \sqrt{5}$
XY= $2 \sqrt{5}$

AD and BC are base1 and base 2
XY=height
so
(b1+b2) times 1/2 times height
( $4 \sqrt{2}+4 \sqrt{5}$ ) times 1/2 times $2 \sqrt{5}$ =
( $4 \sqrt{2}+4 \sqrt{5}$ ) times \sqrt{5} [/tex] =
$4 \sqrt{10}+4*5$ = $4 \sqrt{10}+20$ =80 $\sqrt{10}$ =252.982

X=(15,8)
Y=(13,4)
BC= $4 \sqrt{5}$
XY= $2 \sqrt{5}$
Area=80 $\sqrt{10}$ square unit or 252.982 square units

7 0

3 years ago

Three times the sum of a number and seven is two less than five times the number. . a. 3x+7=5x-2. b. 3(x+7)=5x-2. c. 3(x+7)=2-5x

Nuetrik [128]

We dissect each statement from the problem above to fully understand it.

the sum of a number and 7 is (x + 7)

3 times this is 3(x + 7)

is means the equal sign here 3(x + 7) = 

Two less then 5 times the number is 5x - 2.

Therefore, the answer is B, 3(x + 7) = 5x - 2

5 0

3 years ago

The first step for deriving the quadratic formula from the quadratic equation, 0 = ax2 + bx + c, is shown. Step 1: –c = ax2 + bx

Goshia [24]

Answer:

Subtract c from each side, using the subtraction property of equality

Step-by-step explanation:

0 = ax^2 + bx + c

Subtract c from each side, using the subtraction property of equality

-c = ax^2 + bx + c-c

-c = ax^2 + bx

4 0